Organizing a children's birthday party for others for the first time – do I have to register a business?

I used to work as a daycare teacher. Recently, the parents of one of my former children approached me and asked if I could help plan a birthday party and entertain the children for payment.

I enjoy doing this and could even imagine making a business out of it if it goes well.

The question is, do I need to register a business on this first attempt? And possibly also need insurance?

I think this is all a bit excessive, as the effort would be disproportionate to what I'm doing once. If it becomes a permanent activity, fine. But do I really need to put in the effort for a one-time party?